Ngidi and Pant take Smart Stats honours

Stats editor Every week the Numbers Game takes a look at the story behind the stats, with an original slant on facts and figures. The column is edited by S Rajesh, ESPNcricinfo's stats editor in Bangalore. He did an MBA in marketing, and then worked for a year in advertising, before deciding to chuck it in favour of a job which would combine the pleasures of watching cricket and writing about it. The intense office cricket matches were an added bonus.

With 11 wickets in seven games at an average of 14.18 and an economy rate of six, Lungi Ngidi was clearly the star performer with the ball for Chennai Super Kings, and a key factor in them going on to lift their third IPL title. Ngidi wasn't picked for the first seven matches that Super Kings played, and then sat out two more as conventional wisdom suggested he was far too raw and inexperienced to be effective in the 20-over format in batsman-friendly conditions. However, when he did play, he turned all those theories on their head.

Among the 42 bowlers who bowled at least 25 overs in the tournament, Ngidi's conventional economy rate of six runs per over was the best. But that economy rate was even more impressive because Ngidi bowled the tough overs more often than not: of the 26 overs he bowled, 15 were in the Powerplays, and ten at the death (last five overs). In the Powerplays, he had figures of 5 for 84 in 15 overs, and at the death 4 for 68 in 10. The only over he bowled in the middle stages of an innings was effective too, as he took two wickets in the 11th over - of Shreyas Iyer and Rishabh Pant - against Delhi Daredevils.

Graphic: The most and least valuable runs in IPL 2018. Smart Runs Index calculates the runs by which a batsman has outperformed the average batsman coming in at the same stage of innings ESPNcricinfo Ltd

Because Ngidi bowled so many tough overs, his Smart Economy Rate was by far the best among these 42 bowlers. Smart Economy Rate, one in a set of new metrics developed by ESPNcricinfo to rate T20 performances, takes into account the match economy rate, plus the economy rates of the phase and the previous over when measuring a bowler's performance. Taking those factors into account, Ngidi's Smart Economy Rate (SER) was 3.77, easily the best among the lot; next-best was Jasprit Bumrah's 5.47, followed by the two Afghanistan spinners, Rashid Khan (5.75) and Mujeeb Ur Rahman (5.78). In the 26 overs he bowled, Ngidi conceded 58 fewer than the par value, given the match context.

At the bottom of the pile are the bowlers who have gone for plenty. Mohit Sharma's SER is a staggering 11.92, while Jaydev Unadkat and Dwayne Bravo both had disappointing seasons, with smart economies of more than 10.25.

Graphic: The most and least economical bowlers in IPL 2018. Smart Economy Rate is the ER adjusted to take into account match rate, plus the phase when the overs were bowled ESPNcricinfo Ltd

Among the batsmen, the top run-scorers were all there, led by Delhi Daredevils' Rishabh Pant. His Smart Runs Index - which calculates the number of extra smart runs he scored per innings compared to the average batsman to came in at the same point of entry (in terms of balls remaining in the innings) - for the tournament was 31.81, the highest among batsmen who faced 120-plus balls in the tournament. His Smart Strike Rate - which takes into account the match strike rate, plus the scoring rate at the other end when he was at the crease - was an incredible 207.09, and he scored 132 runs above par in the 394 balls he faced.

KL Rahul made it a 1-2 for Indian batsmen at the top, with a Smart Runs Index of 27.05, but the next three positions in the top five went to overseas batsmen - Jos Buttler, AB de Villiers, and Kane Williamson, who all had outstanding tournaments.

The tournament champions, Chennai Super Kings, didn't have a single batsman in the top five, but they had three in the top ten, thanks to MS Dhoni (SRI 12.62), Shane Watson (11.81) and Ambati Rayudu (11.52). None of the other teams had three batsmen in the top ten. Those three batsmen shared the run-scoring workload, and ensured that the team didn't miss Suresh Raina, who had a relatively quiet tournament, with an SRI of 0.51.